P550 Non-Mag Drill Collar
Chemical Composition
P550 is a special non-mag, austenitic Mn-Cr-N-steel
with a high nitrogen content
|
C |
Mn |
Cr |
Mo |
N |
|
max. 0.06 |
20.50-21.60 |
18.30-20.00 |
min. 0.50 |
min. 0.60 |
Mechanical Properties
Following mechanical properties are achieved by a special
cold-working process over the
full length of the collar:
|
Yield Strength (min.) OD up to
6 7/8“ |
140 ksi
|
965 N/mm² |
|
0.2%-offset method
OD = 7" and larger |
130 ksi |
900 N/mm² |
|
Tensile Strength (min.) |
150 ksi |
1035 N/mm² |
|
Elongation (min.) |
20 % |
20 % |
|
Reduction of Area (min.) |
50 % |
50 % |
|
Impact Energy (min.) |
60 ft.lb |
82 J |
|
Endurance Strength/N=105
(min): |
80 ksi |
550 N/mm2 |
|
Hardness Brinell (min.) |
350 - 430 HB |
350 - 430 HB |
Magnetic Properties
Relative permeability: < 1,005
Corrosion Resistance
- Transgranular SCC: Prevented by special surface treatments
( "PLUS" treatment, roller burnishing,
shot peening).
- Intergranular SCC: The
occurrence of material sensitization
is prevented by quenching after warm-forging.
Each collar is tested acc. to ASTM A 262, Pract. A and E,
last edition.
- Pitting Corrosion: Due to a
high chromium and nitrogen content a high resistance to
pitting corrosion is given.
Non-Destructive testing
- Magnetic inspection:
Drill collars are 100% tested by a proprietary probe-testing
process (“Hot Spot“-test).
Magnetic permeability of each collar is certified with the
printout of probe-testing.
- Ultrasonic inspection:
Each collar is ultrasonically inspected acc. to ASTM E 114,
last edition as a minimum level.
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P550 Non-Mag Drill Collars meet all requirements of API Spec. 7, last edition. All tests are carried out
acc. to ASTM-Standards, last editions.
Prepared / released: H. Aigner Date:
Oct 12, 2004
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